Process for the preparation of sterile ophthalmic aqueous fluticasone propionate form a nanocrystals suspensions

ABSTRACT

The present invention relates to an improved process of manufacturing sterile topical ophthalmic aqueous nanosuspensions of nanocrystals of fluticasone propionate Form A. The sterile topical ophthalmic nanosuspensions are useful in the treatment of eye inflammation conditions such as blepharitis, posterior blepharitis, Meibomian gland dysfunction and dry eye through topical administration of said nanosuspensions to eyelids, eyelashes and eyelid margin.

FIELD OF THE INVENTION

The present invention relates to a process for the preparation ofsterile topical ophthalmic nanosuspensions containing nanocrystals offluticasone propionate Form A in an aqueous vehicle. This process isreadily adaptable to preparation for large-scale production and leads tosterile homogeneous aqueous nanosuspensions having a stable particlesize distribution.

The sterile topical ophthalmic aqueous nanosuspensions containingfluticasone propionate Form A nanocrystals are useful in the treatmentof eye inflammation diseases or eye inflammatory conditions throughtopical administration of said nanosuspensions (or nanocrystalssuspensions) to eyelids (e.g. upper and lower lids), eyelashes andeyelid margin.

BACKGROUND OF THE INVENTION

Nanocrystals of fluticasone propionate Form A are nanoplates having the[001] crystallographic axis substantially normal to the surfaces thatdefine the thickness of the nanoplates. The fluticasone propionate FormA nanocrystals are prepared from a commercially available fluticasonepropionate polymorph 1 by the anti-solvent sonocrystallization processdisclosed in WO 2013/169647.

WO 2013/169647 discloses the preparation of nanocrystals of a morphicform of fluticasone propionate (Form A), their purification and also thepreparation of the aqueous suspensions containing said nanocrystals.

Briefly, according to the continuous sonicating flow-through scale-upprocess disclosed by WO 2013/169647 (Example 11 and FIG. 38) thenanocrystals of fluticasone propionate are prepared using antisolventcrystallization under sonication followed by the thermal annealing ofthe nanosuspension; the generated nanocrystals are purified bycontinuous flow centrifugation, the vehicle of the nanosuspension iscentrifuged out, the pellet is re-dispersed in the washing solution andthe dispersion centrifuged again. This washing procedure is repeatedseveral times to achieve the desired level of purification. The pelletis then dispersed into the final formulation composition to obtain thefinal product at required dose strength. However, WO 2013/169647 doesnot report any data related to the sterility tests of thenanosuspension.

The applicant has found that the continuous sonicating flow-throughprocess disclosed by WO 2013/169647 allows to prepare high amounts offluticasone propionate Form A nanocrystals but it is not suitable for alarge-scale preparation of sterile ophthalmic aqueous nanosuspensionsbecause the dispersion of the purified nanocrystals (pellet) into thefinal aqueous vehicle (see FIG. 38) does not allow to produce a finalproduct having the sterility requirements that must be met bypharmaceutical formulations for ocular delivery. Moreover, during thepreparation of large-scale volumes of the nanosuspension it was foundthat, during the mixing of the purified nanocrystals with the finalaqueous vehicle, the nanocrystals tended to form agglomerates that weredifficult to be de-agglomerated therefore making difficulty to obtainhomogeneous nanosuspensions. Moreover, even when some effectivedeaggregation and homogenous nanosuspensions were obtainedextemporaneously, these nanosuspensions exhibited some propensity toreaggregate and to be unstable.

As it is well known, nanoparticles have a high propensity to agglomeratedue to their high surface energy that cause the formation ofagglomerates during the preparation and storage of the nanosuspensions,

Aggregation of the nanoparticles is not only a critical aspect duringthe manufacturing of the suspensions; agglomeration can cause a varietyof issues, for example, inconsistent dosing and patient non-compliance.In particular, for nanosuspensions intended for application onto theeyelids, eyelashes and eyelid margin, agglomeration, may impact thetolerability in patients and potential safety.

Several strategies to ensure proper physical stability of drugnanosuspensions are well known.

For example, stabilizers are usually used, however, the selection of anappropriate stabilizer for a certain drug can be challenging.

US 2018/0117064 discloses the preparation of aqueous suspensionscontaining nanoparticles of a glucocorticosteroid compound and adispersion stabilizer. US 2018/0117064 discloses that the main functionof the stabilizer is to wet the drug particles thoroughly to preventOstwald ripening and agglomeration of the nanosuspension and to form aphysically stable formulation by providing asteric or an ionic barrier.Typical examples of stabilizers used in nanosuspensions are celluloses,poloxamer, polysorbates, lecithin, polyoleate and povidones.

WO 2010/141834 discloses topical ophthalmic formulations of fluticasonepropionate for treating allergic conjunctivitis and/or allergicrhinoconjunctivitis. WO 2010/141834 discloses a variety of formulationsincluding suspensions having a particle size no greater than 30 μm; anexample of vehicle comprises phosphate buffer, propylene glycol,hypromellose, polysorbate 80, edetate disodium and benzalkonium chloride(page 14, lines, 7-15).

However, WO 2010/141834 does not report any method of preparation of theophthalmic formulations and any experimental results related to thestability of the ophthalmic formulations.

WO 2013/025696 discloses the use of high pressure homogenization toprevent formation of drug aggregates in an ophthalmic formulationcontaining an ophthalmic drug suspended in an aqueous vehicle containingat least one wetting agent. In particular the high pressurehomogenization step may be used to prevent the formation of drugaggregates in the ophthalmic formulation when the drug particles arealready present in a micronized form having particle sizes suitable fortopical application; indeed WO 2013/025696 discloses that the highpressure homogenization may be applied to a suspension containing thepre-micronized drug in the aqueous solution of wetting agent and thehigh pressure homogenization does not bring about particle sizereduction but instead stabilizes the already micronized drug, and thusprevent the formation of drug aggregates.

However, the process of WO 2013/025696 implies the use of high costinstruments that increases the cost of the dosage form, in addition, theuse of high pressure homogenization could cause degradation of thenanocrystals.

The sonication process is commonly used for deagglomerating anddispersing nanomaterials in aqueous based media, necessary to improvehomogeneity and stability of the suspension. Despite its widespread use,sonication treatment tested during the setting up of the process for thepreparation of the nanosuspensions of the present invention was noteffective to deagglomerate fluticasone propionate nanocrystals.

SUMMARY OF THE INVENTION

Therefore, there is a need to provide a large-scale process for thepreparation of ophthalmic nanosuspensions (nanocrystals suspension)containing fluticasone propionate Form A nanocrystals in an aqueousvehicle.

As a result of studies performed to solve the above-mentioned problem,it was surprisingly found that mixing the nanocrystals of fluticasonepropionate Form A with an aqueous vehicle containing glycerin (glycerol)and boric acid under high-shear, high speed conditions stabilizes thenanocrystals. Without wishing to be bound by any theory, it is believedthat glycerin and boric acid form a complex that behaves as stabilizerof the nanocrystals; the boric acid/glycerol complex prevents theformation of nanocrystals aggregates during the preparation of thenanosuspensions and also stabilizes the nanosuspension during storage.The results of the studies also showed that adding the nanocrystals offluticasone propionate Form A into the final vehicle containing thepre-formed boric acid/glycerol complex leads to a residual aggregationwhich is not observed when the nanosuspension is prepared according tothe process of the present invention wherein glycerol is added after thenanocrystals of Fluticasone propionate are suspended and de-agglomeratedin a vehicle that contains boric acid but no glycerol. When thenanocrystals of Fluticasone propionate are directly suspended andde-agglomerated in a final vehicle that contains the pre-formed boricacid/glycerol complex the stabilizing effect is lost and thede-agglomeration of the nanocrystals is more difficult to achieve and tomaintain during the storage.

Complexes of boric acid with polyhydroxyl compounds (borate-polyolcomplexes) are well known and it is generally known the use ofborate-polyol complexes in ophthalmic composition to enhanceantimicrobial activity.

WO 93/21903 discloses borate-polyol complexes, such as mannitol,glycerol and propylene glycol, as adjunctive disinfecting agent incontact lens disinfecting solutions.

WO 2010/148190 discloses borate-polyol complexes including two differentpolyols to improve preservation of multi-dose ophthalmic compositions.

The present invention relates to a process for the preparation ofsterile topical ophthalmic aqueous suspensions containing fluticasonepropionate Form A nanocrystals that is readily adaptable to large-scalepreparation for commercial production and gives rise to stablenanosuspensions with a homogenous reproducible particle sizedistribution.

For this invention “fluticasone propionate Form A nanocrystals” refer tofluticasone propionate Form A nanocrystals that have mean particle sizefrom 100 nm to 1000 nm, a X-ray powder diffraction pattern includingpeaks at about 7.8, 15.7, 20.8, 23.7, 24.5, and 32.5 degrees 2θ, furtherincluding peaks at about 9.9, 13.0, 14.6, 16.0, 16.9, 18.1, and 34.3degrees 2θ, and wherein the said nanocrystals are nanoplates having the[001] crystallographic axis substantially normal to the surfaces thatdefine the thickness of the nanoplates.

DESCRIPTION OF FIGURES

FIG. 1: the XRPD pattern of fluticasone propionate Form A nanocrystals

FIG. 2: Particle size distribution graph at T=1 week at 40° C.; 0.25%fluticasone propionate Form A nanocrystals in a vehicle containing apre-formed 1% w/w boric acid/0.25% w/w glycerol complex (comparativeexample).

FIG. 3: Particle size distribution graph at T=1 week at 40° C.; 0.25%fluticasone propionate Form A nanocrystals in a vehicle containing apre-formed 1% w/w boric acid 1% w/w glycerol (comparative example).

FIG. 4: Particle size distribution graph at T=1 week at 40° C.,refrigerated for 20 hours storage at 5° C. after initial analysis at 40°C.; 0.25% w/w fluticasone propionate Form A nanocrystals in a vehiclewith 0.25% w/w glycerol (comparative example).

DESCRIPTION OF THE INVENTION

The present invention relates to a process for the preparation ofsterile topical ophthalmic aqueous nanosuspensions containingfluticasone propionate Form A nanocrystals having a mean particle sizefrom 100 nm to 1000 nm and a concentration of fluticasone propionatefrom 0.001% w/w to 1% w/w, said process comprises:

-   -   a) preparing an aqueous vehicle 1 containing: 0.5 w/w        methylcellulose 4000 cP, 1.0% w/w boric acid, 0.1% w/w edetate        disodium dihydrate, 0.055% w/w sodium chloride, 0.01% w/w        benzalkonium chloride, 0.2% w/w polysorbate 80, hydrochloric        acid 1N and/or sodium hydroxide 1N to adjust the pH at 7.3-7.5        and water to 100% w/w;    -   b) mixing an amount of fluticasone propionate nanocrystals form        A having a mean particle size from 100 nm to 1000 nm with an        amount of aqueous vehicle 1 to obtain a slurry containing a        concentration of fluticasone propionate of 2% w/w;    -   c) applying high-shear high-speed mixing to the slurry of        step b) for at least 10 minutes;    -   d) preparing an aqueous vehicle 2 containing: 1.8% w/w glycerin,        0.5% w/w methylcellulose 4000 cP, 1.0% w/w boric acid, 0.1% w/w        edetate disodium dihydrate, 0.055% w/w sodium chloride, 0.01%        w/w benzalkonium chloride, 0.2% w/w polysorbate 80, hydrochloric        acid 1N and/or sodium hydroxide 1N to adjust the pH at 7.3-7.5        and water q.s. to 100% w/w;    -   e) adding an aliquot of the aqueous vehicle 2 to the slurry of        step c) to obtain a concentration of fluticasone propionate of        about 1% w/w;    -   f) applying high-shear, high-speed mixing to the slurry of        step e) till to obtain the targeted mean particle size;    -   g) sterilizing the nanosuspension of step 0 by autoclaving;    -   h) preparing an aqueous vehicle 3 containing: 0.9% w/w glycerin,        0.5% w/w methylcellulose 4000 cP, 1.0% w/w boric acid, 0.1% w/w        edetate disodium dihydrate, 0.055% w/w sodium chloride, 0.01%        w/w benzalkonium chloride, 0.2% w/w polysorbate 80, hydrochloric        acid 1N and/or sodium hydroxide 1N to adjust the pH at 7.3-7.5        and water q.s. to 100% w/w; and sterilizing the aqueous vehicle        3 by filtration;    -   i) aseptically adding an aliquot of the sterile aqueous vehicle        3 to the sterilized nanosuspension of step g) to prepare a        sterile topical ophthalmic aqueous nanosuspensions containing        the targeted concentration of fluticasone propionate        nanocrystals Form A;

wherein the nanocrystals of fluticasone propionate Form A have an X-raypowder diffraction pattern of said nanocrystals includes peaks at about7.8, 15.7, 20.8, 23.7, 24.5, and 32.5 degrees 2θ, further includingpeaks at about 9.9, 13.0, 14.6, 16.0, 16.9, 18.1, and 34.3 degrees 2θ,and wherein the nanocrystals are nanoplates having the [001]crystallographic axis substantially normal to the surfaces that definethe thickness of the nanoplates.

In step c) the high-shear, high speed mixing of the slurry containingthe nanocrystals of fluticasone propionate form A and the aqueousvehicle 1, which does not contain glycerin, is conducted to ensure aneven distribution of the fluticasone propionate nanocrystals to improvethe homogeneity of the final nanosuspension.

Preferably in step c) and in step 0 the high-shear, high-speed mixing isperformed at 6000 RPM.

Preferably the high-shear, high-speed mixing of step f) is applied forat least 10 minutes.

Preferably the sterilization of step g) of the nanosuspension of step f)containing a concentration of fluticasone propionate of 1% w/w isperformed by autoclaving the nanosuspension in glass bottles at about122° C. for about 40 minutes.

Preferably the aqueous vehicles 1 and 2 are filtered through 0.2 μmfilter before their use in step b) and step e) respectively.

Optionally the aqueous vehicle 2 containing glycerin 1.8% w/w may beprepared by adding to an aliquot of vehicle 1 filtered through 0.2 μmfilter an amount of glycerin to obtain a final concentration of glycerinof 1.8% w/w.

Preferably in the final sterile topical ophthalmic aqueousnanosuspensions prepared according to the process of the invention theconcentration of fluticasone propionate is from 0.001% to 0.5% w/w; morepreferably the concentration of fluticasone propionate is 0.5% w/w,0.25% w/w, 0.20% w/w, 0.10% w/w, 0.05% w/w, 0.03% w/w, 0.01% w/w or0.005% w/w; most preferably the concentration of fluticasone propionateis 0.20% w/w or 0.10% w/w or 0.05% w/w.

Alternatively, the process of the present invention may be performedunder fully aseptic manufacturing conditions utilizing sterilizedFluticasone propionate Form A nanocrystals and sterilized vehicles 1 to3, accordingly another embodiment of the present invention relates to aprocess for the preparation of sterile topical ophthalmic aqueousnanosuspensions containing fluticasone propionate Form A nanocrystalshaving a mean particle size from 100 nm to 1000 nm and a concentrationof fluticasone propionate from 0.001% w/w to 1% w/w, said processcomprises:

-   -   a-1) sterilizing fluticasone propionate Form A nanocrystals        having a mean particle size from 100 nm to 1000 nm;    -   b-1) preparing an aqueous vehicle 1 containing: 0.5 w/w        methylcellulose 4000 cP, 1.0% w/w boric acid, 0.1% w/w edetate        disodium dihydrate, 0.055% w/w sodium chloride, 0.01% w/w        benzalkonium chloride, 0.2% w/w polysorbate 80, hydrochloric        acid 1N and/or sodium hydroxide 1N to adjust the pH at 7.3-7.5        and water q.s. to 100% w/w; and sterilizing said aqueous vehicle        1 by filtration;    -   c-1) aseptically mixing an amount of sterilized fluticasone        propionate nanocrystals form A with an amount of the sterilized        aqueous vehicle 1 to obtain a slurry containing a concentration        of fluticasone propionate of 2% w/w;    -   d-1) applying high-shear, high-speed mixing to the slurry of        step c-1) for at least 10 minutes;    -   e-1) preparing an aqueous vehicle 2 containing: 1.8% w/w        glycerin, 0.5% w/w methylcellulose 4000 cP, 1.0% w/w boric acid,        0.1% w/w edetate disodium dihydrate, 0.055% w/w sodium chloride,        0.01% w/w benzalkonium chloride, 0.2% w/w polysorbate 80,        hydrochloric acid 1N and/or sodium hydroxide 1N to adjust the pH        at 7.3-7.5 and water q.s. to 100% w/w; and sterilizing said        aqueous vehicle 2 by filtration;    -   f-1) aseptically adding an aliquot of the sterilized aqueous        vehicle 2 to the slurry of step d-1) to obtain a concentration        of fluticasone propionate of about 1% w/w;    -   g-1) applying high-shear, high-speed mixing to the slurry of        step f-1) till to obtain the targeted mean particle size;    -   h-1) preparing an aqueous vehicle 3 containing: 0.9% w/w        glycerin, 0.5% w/w methylcellulose 4000 cP, 1.0% w/w boric acid,        0.1% w/w edetate disodium dihydrate, 0.055% w/w sodium chloride,        0.01% w/w benzalkonium chloride, 0.2% w/w polysorbate 80,        hydrochloric acid 1N/sodium hydroxide 1N to adjust the pH at        7.3-7.5 and water to 100% w/w; and sterilizing said aqueous        vehicle 3 by filtration;    -   i-1) aseptically adding an aliquot of the sterilized aqueous        vehicle 3 to the nanosuspension of step g-1) to prepare a        sterile topical ophthalmic aqueous nanosuspensions containing        the final concentration of fluticasone propionate nanocrystals        Form A;

wherein the nanocrystals of fluticasone propionate Form A have a X-raypowder diffraction pattern including peaks at about 7.8, 15.7, 20.8,23.7, 24.5, and 32.5 degrees 2θ, further including peaks at about 9.9,13.0, 14.6, 16.0, 16.9, 18.1, and 34.3 degrees 2θ, and wherein thenanocrystals are nanoplates having the [001] crystallographic axissubstantially normal to the surfaces that define the thickness of thenanoplates.

Preferably the fluticasone propionate Form A nanocrystals used in stepa-1) are sterilized by autoclaving a suspension of fluticasonepropionate Form A nanocrystals in water for injection having aconcentration of fluticasone propionate between 2% to 20% w/w;preferably the suspension of fluticasone propionate Form A nanocrystalsin water is autoclaved at about 122° C. for about 30 minutes.

Preferably in step d-1) and step g-1) the high-shear, high-speed mixingis performed at 6000 RPM.

Preferably the high-shear, high-speed mixing of step g-1) is applied forat least 10 minutes.

Preferably in the sterile topical ophthalmic aqueous nanosuspensionsprepared according to the process of the invention the concentration offluticasone propionate is from 0.001% to 0.5% w/w; more preferably theconcentration of fluticasone propionate is 0.5% w/w, 0.25% w/w, 0.20%w/w, 0.10% w/w, 0.05% w/w, 0.03% w/w, 0.01% w/w or 0.005% w/w; mostpreferably 0.20% w/w or 0.10% w/w or 0.05% w/w.

Preferably fluticasone propionate Form A nanocrystals used in theprocess of the present invention are prepared according to a generalmethod reported below that comprises the following steps:

1) preparing a phase I solution comprising: 0.45% w/w fluticasonepropionate polymorph 1, 23.2% w/w polyethylene glycol 400 (PEG 400),68.8% w/w polypropylene glycol 400 (PPG 400), and 7.6% w/w polysorbate80 (Tween 80); and filtering the phase I solution through 0.8/0.2 μmPolyethersulfone (PES) filter;

2) preparing a phase II solution comprising: 0.01% w/w benzalkoniumchloride, 0.40% w/w methyl cellulose 15 cP, 0.1% w/w polyethylene glycol40 stearate (PEG-40 stearate), citrate buffer to pH 3.4 to 3.8 and waterq.s. to 100% w/w, and filtering the phase II solution through 0.8/0.2 μmPolyethersulfone (PES) filter;

3) cooling the filtered phase I and phase II solutions to a temperaturefrom 0 to 4° C.;

4) mixing the phase I and the phase II solutions in a reactor equippedwith ultrasonic transducer (for example QSonica Q2000 Ultrasonictransducer) to obtain a phase III suspension of nanocrystals, wherein:

-   -   the phase I solution and the phase II solution are pumped        continuously into the reactor at flow rates of 600 ml/min (phase        I solution) and 2400 ml/min (phase II solution) respectively to        obtain a phase III suspension;    -   the volumes ratio phase I and phase II is 1:4;    -   the sonication is applied during the mixing with an output power        of 60%;    -   the average temperature of phase III suspension is about 11° C.;

5) low shear mixing phase III suspension of step 4) at sufficient speedto create a vortex, at room temperature for a minimum of 30 minutes inabsence of sonication;

6) annealing the phase III suspension at 40° C. over a period of timenot less than 16 hours;

7) preparing a buffer solution comprising: 0.2% w/w polyethylene glycol40 stearate (PEG-40 stearate), 0.2% w/w polysorbate 80 (Tween 80),0.001% w/w benzalkonium chloride, 0.05% w/w sodium phosphate monobasicmonohydrate, 0.02% w/w sodium phosphate dibasic dihydrate and water q.s.to 100% w/w, having a pH 6.3±0.2; and filtering the buffer solutionthrough 0.8/0.2 μm Polyethersulfone (PES) filter; 8) diluting the phaseIII suspension of step 6) with the filtered buffer solution wherein thevolumes ratio buffer solution and phase III is 1:1;

9) centrifuging the diluted phase III suspension to recover thefluticasone propionate nanocrystals Form A and washing the recoverednanocrystals;

10) washing the collected nanocrystals with water for injection.

When the process of the invention is performed under fully asepticmanufacturing conditions the washed nanocrystal of step 10) aresterilized before their use for the preparation of the sterile topicalophthalmic aqueous nanosuspensions; for example, the washed nanocrystalsare suspended in water for injection at a fluticasone propionateconcentration between 2% to 20% w/w, and autoclaved at about 122° C. for30 minutes.

Another embodiment of the present invention relates to an ophthalmicaqueous nanosuspension administrable topically onto eyelids, eyelashesor eyelid margin and consisting of:

-   -   (a) 0.001% to 1% w/w fluticasone propionate Form A nanocrystals;    -   (b) 0.50% w/w methylcellulose 4000 cP;    -   (c) 0.2% w/w polysorbate 80;    -   (d) 0.10% w/w edetate disodium dihydrate;    -   (e) 1.0% w/w boric acid;    -   (f) 0.9% w/w glycerin;    -   (g) 0.01% w/w benzalkonium chloride;    -   (h) 0.055% w/w sodium chloride;    -   (i) hydrochloric acid (1N) and/or sodium hydroxide (1N) as        adjusting agents in an amount sufficient pH from 7.3-7.5; and    -   (j) water q.s. to 100% w/w,

wherein said nanocrystals of fluticasone propionate Form A have a meanparticle size from 100 nm to 1000 nm and a X-ray powder diffractionpattern including peaks at about 7.8, 15.7, 20.8, 23.7, 24.5, and 32.5degrees 2θ, further including peaks at about 9.9, 13.0, 14.6, 16.0,16.9, 18.1, and 34.3 degrees 2θ, and wherein the nanocrystals arenanoplates having the [001] crystallographic axis substantially normalto the surfaces that define the thickness of the nanoplates.

Preferably, in the topical ophthalmic aqueous nanosuspension theconcentration of fluticasone propionate is from 0.001% to 0.5% w/w, morepreferably the concentration of fluticasone propionate is 0.5% w/w,0.25% w/w, 0.20% w/w, 0.1% w/w, 0.05% w/w, 0.03% w/w, 0.01% w/w or0.005% w/w. Most preferably in the topical ophthalmic aqueousnanosuspension the concentration of fluticasone propionate is 0.1% w/w,0.20% w/w or 0.05% w/w.

Another embodiment of the present invention relates to an ophthalmicaqueous nanosuspension administrable topically onto eyelids, eyelashesor eyelid margin and consisting of:

-   -   (a) 0.1% w/w, or 0.5% w/w, or 0.25% w/w, or 0.20% w/w or 0.05%        w/w fluticasone propionate Form A nanocrystals;    -   (b) 0.50% w/w methylcellulose 4000 cP;    -   (c) 0.2% w/w polysorbate 80;    -   (d) 0.10% w/w edetate disodium dihydrate;    -   (e) 1.0% w/w boric acid;    -   (f) 0.9% w/w glycerin;    -   (g) 0.01% w/w benzalkonium chloride;    -   (h) 0.055% w/w sodium chloride;    -   (i) hydrochloric acid (1N) and/or sodium hydroxide (1N) as        adjusting agents in an amount sufficient pH from 7.3-7.5; and    -   (j) water q.s. to 100% w/w,

wherein said nanocrystals of fluticasone propionate Form A have a meanparticle size from 100 nm to 1000 nm and a X-ray powder diffractionpattern including peaks at about 7.8, 15.7, 20.8, 23.7, 24.5, and 32.5degrees 2θ, further including peaks at about 9.9, 13.0, 14.6, 16.0,16.9, 18.1, and 34.3 degrees 2θ, and wherein the nanocrystals arenanoplates having the [001] crystallographic axis substantially normalto the surfaces that define the thickness of the nanoplates.

Another preferred embodiment of the present invention relates to anophthalmic aqueous nanosuspension administrable topically onto eyelids,eyelashes or eyelid margin and consisting of:

-   -   (a) 0.1% w/w, or 0.20% w/w or 0.05% w/w fluticasone propionate        Form A nanocrystals;    -   (b) 0.50% w/w methylcellulose 4000 cP;    -   (c) 0.2% w/w polysorbate 80;    -   (d) 0.10% w/w edetate disodium dihydrate;    -   (e) 1.0% w/w boric acid;    -   (f) 0.9% w/w glycerin;    -   (g) 0.01% w/w benzalkonium chloride;    -   (h) 0.055% w/w sodium chloride;    -   (i) hydrochloric acid (1N) and/or sodium hydroxide (1N) as        adjusting agents in an amount sufficient pH from 7.3-7.5; and    -   (j) water q.s. to 100% w/w,

wherein said nanocrystals of fluticasone propionate Form A have a meanparticle size from 100 nm to 1000 nm and a X-ray powder diffractionpattern including peaks at about 7.8, 15.7, 20.8, 23.7, 24.5, and 32.5degrees 2θ, further including peaks at about 9.9, 13.0, 14.6, 16.0,16.9, 18.1, and 34.3 degrees 2θ, and wherein the nanocrystals arenanoplates having the [001] crystallographic axis substantially normalto the surfaces that define the thickness of the nanoplates.

The sterile topical ophthalmic aqueous nanosuspensions preparedaccording to the process of the present invention have some advantages,for example better tolerability upon administration onto eyelids (e.g.the upper and lower eyelids), eyelashes or eyelid margin due to thesmall particles sizes and maintenance of drug release over a prolongedperiod of time that allows reducing the amount of the active principleto be administered and, consequently, reducing the systemic exposure tofluticasone propionate as well as reducing the exposure to otherstructure of the eye. As it is well known, corticosteroids have sideeffects such as the increase of the intra-ocular pressure (TOP), theincrease of corneal thickness, mydriasis, ptosis, cataract, glaucoma,adrenal suppression, decrease in bone mineral density; therefore lowsystemic exposure an overall eye are an important advantages of theophthalmic aqueous nanosuspensions prepared according to the process ofthe present invention in particular for therapeutic applications thatrequire long-term or repetitive corticosteroid treatment.

The sterile topical ophthalmic aqueous nanosuspension of the presentinvention has high efficacy and local tolerability without the unwantedside-effects associated with the systemic absorption of the fluticasonepropionate active ingredient.

In another embodiment, the nanosuspension of the present invention maybe used in a method for treating or reducing the symptoms and/orclinical signs associated with eye inflammation diseases or eyeinflammatory conditions such as blepharitis, posterior blepharitis,Meibomian gland dysfunction or dry eye disease by topical administrationof said composition to the eye lids, eye lashes or eye lid margin of asubject in need. Such method for treating blepharitis, posteriorblepharitis, Meibomian gland dysfunction or dry eye disease comprisesthe step of topically administering to a subject's eyelids, eyelashes oreyelid margin an effective amount of the nanosuspension of the presentinvention.

Another embodiment of the invention provides a method of treatment andor reducing the symptoms and/or clinical signs associated withblepharitis, posterior blepharitis, Meibomian gland dysfunction or dryeye disease, the method comprising administering an effective amount ofa pharmaceutical composition to a subject in need thereof wherein thepharmaceutical composition is an ophthalmic aqueous nanosuspensionconsisting of: 0.001% to 1% w/w nanocrystals of fluticasone propionateForm A, 0.50% w/w methylcellulose 4000 cP, 0.2% w/w polysorbate 80,0.10% w/w edetate disodium dihydrate, 1.0% w/w boric acid, 0.9% w/wglycerin, 0.01% w/w benzalkonium chloride, 0.055% w/w sodium chloride,hydrochloric acid 1N and/or sodium hydroxide 1N as adjusting agents inan amount sufficient pH from 7.3-7.5, and water q.s. to 100% w/w,wherein said nanocrystals of fluticasone propionate Form A have a meanparticle size from 100 nm to 1000 nm and a X-ray powder diffractionpattern including peaks at about 7.8, 15.7, 20.8, 23.7, 24.5, and 32.5degrees 2θ, further including peaks at about 9.9, 13.0, 14.6, 16.0,16.9, 18.1, and 34.3 degrees 2θ, and wherein the nanocrystals arenanoplates having the [001] crystallographic axis substantially normalto the surfaces that define the thickness of the nanoplates, wherein theophthalmic aqueous nanosuspension is administered topically to the upperand/or lower eye lid margins, Meibomian gland ducts eyelashes or anyarea of the eye lid anatomy. Preferably the ophthalmic aqueousnanosuspension used in the method of the invention contain aconcentration of fluticasone propionate Form A nanocrystals of 0.5% w/w,0.25% w/w, 0.20% w/w, 0.10% w/w, 0.05% w/w, 0.03% w/w, 0.01% w/w or0.005% w/w; more preferably the concentration of fluticasone propionateForm A nanocrystals in the ophthalmic aqueous nanosuspension is of 0.1%w/w, 0.20% w/w 0.25% w/w, 0.5% w/w, 0.05% w/w or 0.01% w/w; mostpreferably the concentration of fluticasone propionate Form Ananocrystals is 0.1% w/w, 0.20% w/w or 0.05% w/w.

Typical clinical signs associated with blepharitis and Meibomian glanddysfunction include lid debris, redness of eyelid margin, eyelidswelling, obstruction of the Meibomian gland, and orqualitative/quantitative changes in Meibomian gland secretion.

The most common symptoms associated with dry eye, which is also known askeratoconjunctivitis sicca, include eye dryness, eye discomfort, eyeredness, a stinging, burning or scratchy sensation in the eyes, wateryeyes, sensitivity to light, blurred vision, pain or eye fatigue.

The method of the invention is preferably directed to a method fortreating non-infectious, inflammatory blepharitis or Meibomian glanddysfunction in a subject.

In another embodiment, a subject is administered with topical ophthalmicaqueous nanosuspension of the present invention at least once a day,preferably subject is administered with the pharmaceutical formulationonce a day.

In another embodiment, a subject is administered with topical ophthalmicaqueous nanosuspension of the present invention at least once a day forat least two weeks, more than two weeks, at least three weeks, or atleast four weeks.

Another embodiment of the present invention relates to a kit comprising(a) the above reported topical administrable ophthalmic aqueousnanosuspension containing fluticasone propionate Form A nanocrystals and(b) a swab or sponge to apply the nanosuspension to the eyelids,eyelashes or eyelid margin.

EXAMPLES

The percentage (%) as used herein in the compositions and in theexamples refers to weight percentage (w/w) unless otherwise stated. Theterms glycerin and glycerol in the text and in the examples are used assynonyms.

Example 1

Preparation of Nanocrystals of Fluticasone Propionate Form A

Preparation of Phase I Solution

In a 2 L process vessel, 106.26 g polysorbate 80 (Tween 80), 963.34 gpolypropylene glycol 400 (PPG 400), 324.10 g polyethylene glycol 400(PEG 400), were added at room temperature and stirred together until allcomponents were dissolved, then 6.3 g fluticasone propionate polymorph 1was added into the solution and stirred until a clear solution wasobtained. The obtained solution was filtered using a 0.8/0.2 μmPolyethersulfone (PES) filter and kept refrigerated at 2-8° C. untiluse.

Preparation of Phase II Solution

In an 8 L process vessel an initial quantity of about 5276 g of purifiedwater was added and stirred with an over-head mixer so that a vortex wasgenerated.

6.01 g polyethylene glycol 40 stearate (PEG-40 stearate), 5.98 gbenzalkonium chloride (solution 10%), and 24.02 g methyl cellulose 15 cPwere added and stirred till methyl cellulose was completely dissolved.Citrate buffer was added to adjust the pH to 3.5-4.0 and 585.8 g waterwere added. The final pH of the phase II solution was 3.83

Phase II was then filtered using a 0.8/0.2 μm Polyethersulfone (PES)filter and kept refrigerated at 2-8° C. until use.

Preparation of Dilution Buffer Solution

In a 20 L process vessel, 12.0 g polysorbate 80 (Tween 80) wereintroduced, 5374 g purified water were added, and stirred with anover-head mixer so that a vortex was generated.

3.24 g sodium phosphate monobasic monohydrate, 1.14 g sodium phosphatedibasic dihydrate, 12.00 g polyethylene glycol 40 stearate (PEG-40stearate), 0.6 g benzalkonium chloride (solution 10%) were added andstirred until complete dissolution, and 597 g water were added. Thefinal pH of the buffer solution was 6.4. This solution was filteredusing a 0.8/0.2 μm Polyethersulfone (PES) filter and kept refrigeratedat 2-8° C. until use.

Preparation of Nanocrystal of Fluticasone Propionate Form A

480 g of phase II were introduced into the chamber of the reactor. 940 gphase I and 3780 g phase II were allowed to cool down to a targettemperature of 2-4° C. in their jacketed vessels connected to chillers.

Using peristaltic calibrated pumps phase I and phase II were pumped(pump flow rates for phase I and phase II were respectively 600 ml/minand 2400 ml/min) through the reactor fitted with its ultrasonictransducer with an amplitude set at 60% (Q Sonica Q1375 W).

The outflow from the reactor (phase III: 5201.7 g) was collected into aclean vessel at room temperature. The temperature of phase III was about11° C.

Then phase III was stirred at room temperature for about 30 minutes inthe collecting vessel to obtain a uniform suspension of fluticasonepropionate nanocrystals (final phase III).

Annealing Process

The final phase III was transferred into a closed container. Thecontainer was placed in an incubator and maintained at 40° C. for atleast 16 hours.

Purification and Isolation of Nanocrystals

5167 g of the annealed phase III were transferred into a process vesseland an equivalent amount of dilution buffer solution was added, so thatthe ratio of phase III to dilution buffer solution was 1:1. Theresulting mixture was stirred with a low shear mixer for 30 minutes toachieve a homogeneous suspension of nanocrystals (diluted phase III).

The diluted phase III was kept refrigerated at 2-8° C. untilcentrifugation.

The fluticasone propionate Form A nanocrystals were first collected bydiscontinuous centrifugation of the diluted phase III. The nanocrystalswere then washed several times (4 washing cycles) with water forinjection.

The particle size of the isolated nanocrystals was evaluated using alaser scattering Particle size distribution analyzer (Horiba LA-950).The D₅₀ was 0.2153 μm and the D₉₀ was 0.6073 μm

Characterization of the nanocrystals was performed by XRPD and Rietveldrefinement. Results are provided in FIG. 1 (XRPD) showing the typicalpattern of Fluticasone propionate form A, having a crystal habit withstrong preferred orientation and c-axis substantially normal to thesurface, as defined in WO 2013/169647 confirmed by pole figure obtainedfrom Rietveld refinement.

Example 2

Preparation of a Sterile Topical Ophthalmic Aqueous Nanosuspension ofFluticasone Propionate Form A

TABLE 1 Fluticasone propionate nanosuspension composition IngredientsAmount (% w/w) Fluticasone propionate Form A nanocrystals 0.10Methylcellulose 4000 cP 0.50 Polysorbate 80 0.2 Edetate disodium,dihydrate 0.10 Boric acid 1.0 Glycerin 0.9 Benzalkonium chloride 0.01Sodium chloride 0.055 Water for injection q.s. to 100% pH 7.3-7.5

Step 1) Preparation of Vehicle 1 (Vehicle without Glycerin)

In a 20 L process vessel, 17600 g water for injection were heated at 80°C., 100.0 g methylcellulose 4000 cP were slowly added and the mixture isstirred until methylcellulose was dissolved.

The solution was cooled at 40° C., 200.0 g boric acid was added and thepH was adjusted at 7.4 with sodium hydroxide (1N).

The following excipients were added in the specific following order:20.0 g edetate disodium dihydrate, 11.0 g sodium chloride, 4.0 gbenzalkonium chloride (solution 50%), 40.0 g polysorbate 80 (Tween 80);each excipient being fully dissolved before adding the next excipientand the preparation of the solution is carried out at a temperature ofabout 40° C. to room temperature. The pH was tested and optionallyadjusted at 7.3-7.5 with hydrochloric acid (1N) or sodium hydroxide(1N); after the pH adjustment, water for injection was added to bringthe final weight to 19800 g. The resulting solution was mixed for atleast 10 minutes to obtain a uniform solution which was stored at 2-8°C.

Step 2) Preparation of the 2% Fluticasone Propionate Nanocrystals Slurry

4000 g of vehicle 1 were introduced into a 10 L process vesselcontaining a stir bar, by filtration through a PES 0.2 μm media and wereset aside for further use. In a 2 L beaker, 15.04 g of the fluticasonepropionate Form A nanocrystals were introduced together with somevehicle 1. This slurry was mixed for homogeneity and assayed forfluticasone propionate content (31.6 mg/g), then it was further dilutedwith vehicle 1 so as to achieve a target concentration of fluticasonepropionate of 20 mg/ml (2% w/w slurry). This concentrated slurry wassubject to high-shear, high-speed mixing at 6000±10 RPM for 10 minutesand the particle size distribution was tested by laser diffraction on aHoriba LA-950S2 PSD analyzer.

The results were the following:

-   -   Mean: 0.856 μm    -   Mode: 0.363 μm    -   Median: 0.420 μm    -   D₁₀: 0.203 μm    -   D₉₀: 2.154 μm

Step 3) Preparation of Vehicle 2 (Vehicle Containing Glycerin 1.8% w/w)

In a 4 L beaker, 1600 g of the filtered vehicle 1 were introduced, and36 g glycerin were added under stirring until dissolution.

The pH was tested and adjusted at 7.3-7.5 with sodium hydroxide (1N) andvehicle 1 was further added to adjust the final weight to 2000 g,leading to a 1.8% w/w glycerin solution.

Step 4) Preparation of the 1% Fluticasone Propionate Nanocrystals Slurry

The 1% fluticasone propionate nanocrystals slurry was prepared byfurther diluting the 2% concentrated slurry prepared in Step 2) withvehicle 2 down to a concentration of fluticasone propionate of 1% w/w.

The 1% w/w fluticasone propionate Form A nanocrystals slurry was subjectto high-shear, high-speed mixing at 6000±10 RPM for 10 minutes and theparticle size distribution was tested by laser diffraction using aHoriba LA-95052 PSD analyzer.

The results were the following:

-   -   Mean: 0.428 μm    -   Mode: 0.123 μm    -   Median: 0.162 μm    -   D₁₀: 0.082 μm    -   D₉₀: 0.678 μm

Aliquots of the 1% concentrated slurry were filled into 500 ml glassbottles containing stir bar and sterilized by autoclaving at 121.5° C.for 40 minutes.

Step 5) Preparation of Vehicle 3 (Vehicle Containing Glycerin 0.9% w/w)

In a 20 L container, 11200 g of vehicle 1 were introduced, 126 g ofglycerin were added under stirring and the pH was then adjusted withsodium hydroxide to 7.3-7.5 and an aliquot of vehicle 1 was furtheradded to adjust the final weight to 14000 g, leading to a 0.9% w/wglycerol solution. This solution was mixed for at least 10 minutes untiluniform and sterile filtered into another receiving vessel.

Step 6) Preparation of the 0.1% w/w Fluticasone PropionateNanosuspension.

In an ISO 5 environment, the content of the bottles containing theautoclaved sterile 1% w/w fluticasone propionate nanocrystals of Step 4)were aseptically transferred and pooled into a final compounding vessel.

The weight of the 1% fluticasone propionate nanocrystals slurrytransferred in the vessel was recorded (1366.3 g).

The final 0.1% sterile fluticasone propionate nanocrystal suspension wasobtained by adding 11774.2 g of the sterile vehicle 3.

The final sterile nanosuspension was stirred for not less than 15minutes on a stir plate.

The particle size distribution was tested by laser diffraction using aHoriba LA-950S2 PSD analyzer.

The results were the following:

Mean: 0.846 μm

-   -   Mode: 0.362 μm    -   Median: 0.425 μm    -   D₁₀: 0.202 μm    -   D₉₀: 2.219 μm

Nanosuspensions according to the invention containing differentconcentrations of fluticasone propionate form A such as 0.5% w/w, 0.25%w/w, 0.20% w/w, 0.1% w/w, 0.05% w/w, 0.03% w/w, 0.01% w/w and 0.005% w/wwere obtained by diluting the de-agglomerated 1% fluticasone propionatenanosuspension of step 4) with aliquots of aqueous vehicle 3 asdisclosed in step 6) to obtain the final fluticasone propionateconcentration.

Example 3

Evaluation of the Stability of the Nanosuspension of Example 2

The nanosuspension composition prepared in example 2 was subjected tostorage stability testing by storing the nanosuspension at threedifferent temperatures and humidity conditions (5° C., 25° C./40% RH;40° C./25% RH) The resuspendability of the nanosuspension, the contentof fluticasone propionate, the particle size distribution and thecontent of benzalkonium chloride were assessed at 1 month and 3-monthtime-points.

The results reported in tables 2 and 3 show that the nanosuspension wasphysically and chemically stable upon manufacture and storage. No changein physical appearance of the nanosuspension upon storage was noticed.The nanosuspension did not show any sign of chemical degradation as thechemical assay of fluticasone propionate was well within the limit of90%-110% of the label claim upon storage. The related substances andtotal impurities remained within the specified limits of not more than4%, upon storage.

TABLE 2 1-month time-point stability data T = 1 month T0 25° C. 40° C.Parameter n/a 5° C. 40% RH 25% RH Fluticasone propionate 105.6% 103.8%98.2% 101.2% assay Fluticasone Propionate 0.0%  0.25% 0.10%  0.11%Related substances (total) Resuspendability n/a Readily Readily Readilyresuspends resuspends resuspends BAK content 99.1%   98%   97%   98% PSDresults (μm) Mean 0.846 0.816 0.796 0.825 Median 0.425 0.461 0.412 0.455Mode 0.362 0.366 0.363 0.366 D₁₀ 0.202 0.213 0.200 0.212 D₉₀ 2.219 1.7311.991 1.866

TABLE 3 3-month time-point stability data T = 3 months T0 25° C. 40° C.Parameter n/a 5° C. 40% RH 25% RH Fluticasone 105.6% 103% 104% 104%propionate assay FP Related 0.0% 0.11%  0.12%  0.11%  substances (total)Resuspendability n/a Re- Re- Re- suspends suspends suspends BAK content99.1% 101% 101%  97% PSD results (μm) Mean 0.846 0.830 0.830 0.770Median 0.425 0.460 0.480 0.330 Mode 0.362 0.370 0.420 0.320 D₁₀ 0.2020.220 0.230 0.170 D₉₀ 2.219 1.980 1.890 2.250

Example 4 (Comparative Example)

The results of this study show that nanosuspensions of fluticasonepropionate Form A nanocrystals containing boric acid but no glycerin arenot stable and aggregate.

Fluticasone propionate Form A nanocrystals were suspended in a vehiclecontaining the exact same concentrations of boric acid and ofmethylcellulose as in the previous Example 2 but it does not containglycerol.

The compositions of the tested nanosuspensions are reported in Table 4.

TABLE 4 Tested nanosuspensions Ingredient Concentration (% w/w)Fluticasone Propionate 0.1 0.03 0.01 0.005 N/A Methylcellulose 4000 cP0.5 0.5 0.5 0.5 0.5 Polysorbate 80 0.2 0.2 0.2 0.2 0.2 (Tween 80)Edetate disodium, 0.1 0.1 0.1 0.1 0.1 dihydrate Boric acid 1.0 1.0 1.01.0 1.0 Sodium chloride 0.055 0.055 0.055 0.055 0.055 Glycerin 0 0 0 0 0Benzalkonium chloride 0.01 0.01 0.01 0.01 0.01 Water for Injection q.s.q.s. q.s. q.s. q.s. to 100 to 100 to 100 to 100 to 100

Preparation of the Fluticasone Propionate Form A Nanocrystal Suspensions

An amount of Fluticasone propionate Form A nanocrystals were suspendedin aliquots of vehicle consisting of: 0.50% w/w methylcellulose 4000 cP,0.2% w/w polysorbate 80, 0.10% w/w edetate disodium dihydrate, 1.0% w/wboric acid; 0.01% w/w benzalkonium chloride and water q.s to 100% w/w(see Table 4), to get the targeted concentrations of fluticasonepropionate (see Table 4). Once the nanocrystals were suspended, thesuspension was poured into a 500 mL glass beaker for deagglomerationusing a high-speed, high-shear Silverson mixing apparatus. Thesuspension was mixed at 6000 RPM until particle size distributionspecifications were met. The particle size distribution and theviscosity of the nanosuspensions were measured.

The nanosuspensions were placed on stability at 40° C., the particlesize distribution (PDS) and the viscosity were measured at 2-week timepoint.

The results reported in Tables 5a and 5b show that over a short periodof two weeks only, there was an increase of the mean particle size andof the D₉₀, reflecting the formation of aggregates in thenanosuspensions; conversely the stability results reported in Example 3show that the nanosuspension prepared according to the process of theinvention was stable under accelerated conditions up to 3 months.

TABLE 5a PSD and viscosity assessments Time T0 2 weeks Formulationcontaining 0.1% of Fluticasone propionate Viscosity in cP 18.6 15.7Particle Size Distribution results in μm Mode 0.212 0.183 Median 0.2450.261 Mean 0.382 2.575 D₁₀ 0.137 0.261 D₉₀ 0.754 7.571 Formulationcontaining 0.03% of Fluticasone propionate Viscosity in cP 19.7 15.6Particle Size Distribution results in μm Mode 0.317 0.210 Median 0.3190.291 Mean 0.437 2.128 D₁₀ 0.161 0.141 D₉₀ 0.829 6.279

TABLE 5b PSD and viscosity assessments Time T0 2 weeks Formulationcontaining 0.01% of Fluticasone propionate Viscosity in cP 19.7 15.1Particle Size Distribution results in μm Mode 0.319 0.317 Median 0.3360.467 Mean 0.463 1.808 D₁₀ 0.179 0.197 D₉₀ 0.854 4.719 Formulationcontaining 0.005% of Fluticasone propionate Viscosity in cP 19.3 16.3Particle Size Distribution results in μm Mode 0.319 0.318 Median 0.3370.427 Mean 0.382 1.050 D₁₀ 0.179 0.190 D₉₀ 0.931 2.619 Formulationcontaining 0.0% of Fluticasone propionate Viscosity in cP 18.6 16.6

Example 5 (Comparative Example)

The results of this study confirmed that adding the Fluticasonepropionate Form A nanocrystals into a vehicle containing the pre-formedboric acid/glycerol complex leads to a residual aggregation which is notobserved when the nanosuspension is prepared according to the process ofthe present invention wherein the glycerol is added to the high speedhigh, shear mixing de-agglomerated 2% fluticasone propionatenanocrystals slurry (see Example 2—Step 4).

Fluticasone propionate Form A nanocrystals were suspended andde-agglomerated in the vehicle containing the pre-formed boricacid/glycerol complex (boric acid 1.0% w/w/glycerol 0.25% w/w and boricacid 1.0% w/w/glycerol 1.0% w/w) to get a final concentration ofFluticasone propionate of 0.25% w/w.

The compositions of the vehicles of the two tested nanosuspensions arereported in Table 6.

TABLE 6 Tested nanosuspensions Ingredient Concentration (% w/w)Fluticasone Propionate 0.25 0.25 Methylcellulose 4000 cP 0.5 0.5 Tween80 0.2 0.2 EDTA disodium, dihydrate 0.1 0.1 Boric acid 1.0 1.0 Sodiumchloride 0.05 0.05 Glycerol 0.25 1.0 Benzalkonium chloride 0.01 0.01Water for Injection q.s. to 100 q.s. to 100

Preparation of the Fluticasone Propionate Form A NanocrystalNanosuspensions

Fluticasone propionate Form A nanocrystals were suspended in the twovehicles reported in Table 6 that contain the pre-formed boricacid/glycerol complex and stirred overnight on a magnetic stir plate,using a stir bar. Once the nanocrystals were suspended, the suspensionwas poured into a 500 mL glass beaker for de-agglomeration using ahigh-speed, high-shear, Silverson mixing apparatus. The suspension wasmixed at 6000 RPM until particle size distribution specifications weremet.

The two formulations were placed on stability at 40° C. and theparticles size distribution was measured on samples pulled out at 1-weektime point. The samples were analyzed shortly after being pulled fromthe stability chamber. The results show a great deal of aggregation inthe samples (see FIGS. 2 and 3).

The aggregation was partly reversible when the samples were refrigeratedbut there still was a substantial residual level of aggregation (seeFIG. 4); this thermo-reversible aggregation was related to the decreaseof the solubility of the methylcellulose when the temperature increases.It is known that even though methylcellulose solutions are visuallyclear with no detectable particles in the range of 30−50° C., thepolymer chains form loosely-associated clusters that grow in size as thetemperature increases. These clusters are likely responsible for part ofthe aggregation of the nanocrystals at 40° C.

As reported above, the results of this study demonstrated that glycerolacts as a stabilizer by forming a complex with the boric acid thatprevents the aggregation of the isolated nanocrystals. If thenanosuspension is prepared by suspending the nanocrystals in the vehiclethat contains the pre-formed complex boric acid/glycerol, thestabilizing effect of the complex is reduced.

Example 6

In Vitro Dissolution Test

The dissolution rate of the Fluticasone propionate form A nanocrystalsof the nanosuspension of the invention was assessed and compared to thedissolution rate of a standard Fluticasone propionate form 1 micronizedmaterial (reference sample).

Dissolution profiles of nanocrystals of Fluticasone propionate form A oftwo nanosuspensions of the invention and of Fluticasone propionate form1 micronized were performed using a dissolution method.

The particle size of the Fluticasone propionate Form A nanocrystals is0.434 μm (D50—median) and the particle size of the Fluticasonepropionate form 1 micronized material is 4.64 μm (D50—median).

The study was performed using a compartment diffusion analysis through adialysis membrane and sink condition. The sink condition was achievedthrough the use of a receptor fluid containing 30 mM phosphate buffer,pH 7.4 with 5% HPβCD cyclodextrins and also by a complete replacement ofthe buffer every 24 hours to stay below the saturation point. Thesaturation point was estimated to be 5 μg/g under those experimentalconditions and the measurements performed as well as the bufferreplacement have shown a maximum concentration of 1.5 μg/g. The studywas conducted at a temperature of 37° C. The details of the dissolutiontest method are provided below:

A 5-fold dilution with the formulation vehicle (placebo solutioncontaining all the formulation excipients including the surfactants) oftwo 0.1% w/w Fluticasone propionate form A nanosuspensions was conductedto obtain a final concentration of 0.02% w/w Fluticasone propionateinside the dialysis device.

Fluticasone propionate form 1 micronized was suspended in the samephosphate buffer used in the receiving compartment of the dialysissystem.

Fluticasone propionate release was carried at 1-2 RPM.

Sampling aliquots of 1 mL were withdrawn at pre-determined timeintervals (1, 3, 5, 20, 24, 48, 72 hours), and replaced with an equalvolume of dissolution medium to maintain a constant total volume of 39ml in the 50 ml tube.

These aliquots were immediately centrifuged and the measurements wereperformed by HPLC

The results reported in tables 7-9 show that the dissolution profiles ofthe nanocrystals of Fluticasone propionate form A and of the Fluticasonepropionate form 1 micronized material were similar despite that the twotest samples and the reference sample have different particle size. Morespecifically, the particle size of Fluticasone propionate Form Ananocrystals is ten-fold smaller (D₅₀=0.434 μm) than the particle sizeof the micronized Fluticasone propionate form 1 (D₅₀=4.64 μm).

Since, the solubility of a compound is often intrinsically related tothe particle size, as a particle becomes smaller, the surface area tovolume ratio increases leading to greater interaction with the solventwhich causes an increase in solubility, the results of this study showthe unique property of the ophthalmic aqueous fluticasone propionateForm A nanocrystals of the invention, namely on one hand the smallparticle size (nanoparticles) improves the comfort and the tolerabilityof the ophthalmic formulation, on the other hand the slow dissolutionrate of the fluticasone propionate active principle allows to avoid afast and high absorption of fluticasone propionate correlated to theunwanted side-effects associated with the systemic absorption of thesteroid.

TABLE 7 Dissolution test of Fluticasone propionate form A nanocrystalsTime % Dissolution point St. (h) Tube #1 Tube #2 Tube #3 Average % Dev.RSD 1 0.0% 0.0% 0.0% 0.0% 0.0% 3 0.2% 1.4% 0.7% 0.8% 0.6% 73.2% 5 1.3%2.8% 2.4% 2.2% 0.8% 35.6% 19 14.5% 20.4% 18.7% 17.8% 3.0% 16.9% 24 17.5%24.0% 22.4% 21.3% 3.4% 15.9% 48 38.7% 51.4% 48.6% 46.2% 6.7% 14.4% 7259.6% 78.1% 74.0% 70.5% 9.7% 13.7%

TABLE 8 Dissolution test of Fluticasone propionate form A nanocrystalsTime % Dissolution point St. (h) Tube #1 Tube #2 Tube #3 Average % Dev.RSD 1 0.0% 0.0% 0.0% 0.0% 0.0% 3 0.6% 0.5% 0.8% 0.7% 0.2% 26.7% 5 2.4%2.0% 2.6% 2.3% 0.3% 11.2% 19 19.0% 18.2% 19.7% 19.0% 0.8% 4.1% 24 22.4%21.5% 23.2% 22.4% 0.9% 3.8% 48 49.1% 45.6% 50.9% 48.5% 2.7% 5.6% 7275.1% 69.1% 77.7% 73.9% 4.4% 6.0%

TABLE 9 Dissolution test of Micronized Fluticasone propionate form 1Time % Dissolution point St. (h) Tube #1 Tube #2 Tube #3 Average % Dev.RSD 1 0.0% 0.0% 0.0% 0.0% 0.0% 3 0.8% 0.5% 0.9% 0.7% 0.2% 31.2% 5 2.9%1.9% 3.0% 2.6% 0.6% 23.1% 19 20.9% 17.1% 20.3% 19.4% 2.1% 10.7% 24 24.2%20.2% 23.5% 22.6% 2.2% 9.5% 48 51.1% 44.0% 50.6% 48.6% 4.0% 8.2% 7277.4% 66.7% 76.2% 73.4% 5.9% 8.0%

Example 7

14-Day Repeated Dose Study of Topical Ophthalmic Aqueous FluticasonePropionate Form A Nanocrystals Suspensions in Beagle Dogs

The purpose of this study was to evaluate the toxicokinetic offluticasone propionate Form A nanosuspensions of the invention (seeTable 10 below) administered via topical application directly to the rim(margin) of upper and lower eyelids of both eyes of Beagle dogs.

TABLE 10 Test formulations composition Ingredient % (w/w) % (w/w) %(w/w) % (w/w) Fluticasone Propionate 0.00 0.005 0.03 0.1 Methylcellulose4000 cP 0.50 0.50 0.50 0.50 Tween 80 0.20 0.20 0.20 0.20 Edetatedisodium, 0.10 0.10 0.10 0.10 dihydrate Boric acid 1.00 1.00 1.00 1.00Sodium chloride 0.055 0.055 0.055 0.055 Glycerol 0.90 0.90 0.90 0.90Benzalkonium chloride 0.01 0.01 0.01 0.01 Water for Injection q.s. to100 q.s. to 100 q.s. to 100 q.s. to 100

Methods

Fifty naïve Beagle dogs (25 males and 25 females), approximately 5-6months old and weighing 5.7 to 8.8 kg for males and females at theoutset of the study were assigned to treatment groups (groups 1-4) andto vehicle group.

Male and female Beagle dogs were dosed with fluticasone propionate at1.6, 9.6, and 32 μg/day (bilateral QD topical application) or at 64μg/day (bilateral BID topical application) via eye lid applicatordirectly to the upper and lower eyelids of both eyes once or twice daily(minimum of 6 hours between doses) for 14 consecutive days.

Blood for toxicokinetic evaluation was collected from all animals atselected time points on Days 1 and 14.

Ophthalmology examinations were performed prior to treatment initiation,during the first and second weeks of dosing and during the last week ofrecovery. Eyes were scored once daily according to the modified Draizescale.

The reversibility of the effects of Fluticasone Propionatenanosuspension was assessed with a 14-day recovery period.

Results and Conclusions

The group mean plasma toxicokinetic parameters are summarized in Table11 below.

The results show that exposure to fluticasone propionate wasdose-dependent increasing with increasing doses. There was no clearevidence of accumulation in male and female animals. There were nodiscernable gender-related differences in exposure. Systemic exposure(AUC) at the lowest observed adverse effect level associated withcorticosteroid-related findings in a 14-day inhalation toxicity study indogs was 14- and 9-times higher than that observed at the ocular dose of0.1% QD and BID, in the 14-day topical ocular toxicity study in dogs(Advair-Diskuss-NDA-021077).

There was no evidence of local or systemic toxicity.

TABLE 11 Plasma Toxicokinetic Parameters of Fluticasone Propionatefollowing topical ocular eyelid margin administration Study Ocular DoseTmax Cmax AUC₀-24 h Day Treatment (μg/day) (h) (pg/mL) (pg · h/mL) 10.005% QD 1.6 0.5 32.4 ± 26.4 25.7 ± 18.5 0.03% QD 9.6 0.5 79.8 ± 70.0101 ± 102 0.1% QD 32 0.5 250 ± 219 482 ± 407 0.1% BID 64 6.5 304 ± 178914 ± 413 14 0.005% QD 1.6 0.75 28.1 ± 26.6 56.8 ± 65.0 0.03% QD 9.6 0.560.8 ± 48.7 191 ± 335 0.1% QD 32 0.5 130 ± 155 481 ± 361 0.1% BID 64 0.5 126 ± 93.6 760 ± 188

Example 8

Evaluation of Efficacy and Safety of Fluticasone Propionate Form aNanosuspension for the Treatment of Acute Exacerbations of Blepharitis

The objective of this study was to compare the efficacy and safety of anaqueous ophthalmic formulation of Fluticasone propionate form Ananosuspension of the invention versus placebo in reducing signs andsymptoms in subjects with blepharitis.

Test Formulation (Hereafter FP-Form A-NS)

0.1% w/w fluticasone propionate Form A nanocrystals (mean particle sizefrom 100 nm to 1000 nm) 0.50% w/w methylcellulose 4000 cP, 0.2% w/wpolysorbate 80, 0.10% w/w edetate disodium dihydrate, 1.0% w/w boricacid, 0.9% w/w glycerin, 0.01% w/w benzalkonium chloride, 0.055% w/wsodium chloride, hydrochloric acid (1N) and/or sodium hydroxide (1N) asadjusting agents in an amount sufficient for pH from 7.3-7.5, and waterq.s. to 100% w/w.

Placebo Formulation

0.50% w/w methylcellulose 4000 cP, 0.2% w/w polysorbate 80, 0.10% w/wedetate disodium dihydrate, 1.0% w/w boric acid, 0.9% w/w glycerin,0.01% w/w benzalkonium chloride, 0.055% w/w sodium chloride,hydrochloric acid (1N) and/or sodium hydroxide (1N) as adjusting agentsin an amount sufficient for pH from 7.3-7.5, and water q.s. to 100% w/w.

Study Design

This was a Phase 2 multi-center, randomized, double-masked,placebo-controlled study evaluating the safety and efficacy offluticasone propionate Form A nanosuspension 0.1% once a day for thetreatment of the signs and symptoms of blepharitis.

The target population in this study was adult men and women with adocumented history of blepharitis who were experiencing an acuteblepharitis exacerbation defined as a minimum score of ‘1’ (on a 4-pointscale) for each of Eyelid Margin Redness, Eyelid Debris, and EyelidDiscomfort in both eyes at the Screening and Baseline Visits. A total of15 subjects were included in the study. Subject ages were between 55 and80 years old, with an average age of 70.8 years.

Fifteen patients have been randomized at three clinical sites across theU.S. Ten patients received FP-Form A-NS and 5 patients received placebo,once a day in the evening for both eyes.

Study visits were as follows: Screening (Day −7 to −3), Baseline/Day 1,Day 4 (±1 day), Day 8 (±1 day), Day 11 (±1 day), Day 14 (−1 day; lastday of treatment), and Day 28/Exit (±2 days; follow up visit).

Test nanosuspension (16 μg of fluticasone propionate per eye) or placebowere applied once a day in the evening. Study drug was self-administeredby the subjects.

Evaluation of the Efficacy and Safety of the Fluticasone Propionate Forma Nanosuspension

Efficacy and safety of fluticasone propionate form A nanosuspension(FP-Form A-NS) were compared with placebo at each post-dose visit duringthe study. In addition of signs and symptoms of blepharitis, this studyevaluated signs and symptoms characteristic of dry eye disease, alsocommonly observed in subjects with blepharitis.

Efficacy

The results of the study reported in Tables 12 and 13 demonstrated thatfluticasone propionate form A nanosuspension treatment consistentlyimproved the signs and symptoms in subjects with blepharitis and thatsubjects treated with fluticasone propionate form A nanosuspensionshowed a decrease in the composite score of debris, redness anddiscomfort from baseline and versus subjects treated with placebo.

The results presented in Tables 12 and 13 are related to signs andsymptoms of blepharitis in the study eye evaluated after 14 days oftreatment and conducted prior to daily eyelid scrub procedures.

The following dry eye symptoms were also evaluated with Visual AnalogScales (VAS) by the subjects: eye dryness, burning-stinging, foreignbody sensation, itching, photophobia, pain and blurred vision. Thecomposite VAS score (the average of individual scores of these symptoms)reported in Table 14 demonstrated that fluticasone propionate Form Ananosuspension treatment was efficacious in reducing dry eye symptomswith respect to placebo.

Safety

The treatment with fluticasone propionate Form A nanosuspension of theinvention was very well tolerated, all patients completed the treatment.There were no Serious Adverse Events (SAEs) and in particular, noclinically relevant changes in subject's intraocular pressure wereobserved during treatment or up to two weeks after treatmentdiscontinuation.

The results of this study demonstrate that fluticasone propionate Form Ananosuspension of the invention is able to reduce both signs andsymptoms of blepharitis and dry eye and that the treatment andapplication method have a safe tolerability profile.

TABLE 12 Signs and symptoms of blepharitis at Day 14 of treatment withfluticasone propionate form A nanosuspension of the invention (FP-FormA-NS) versus placebo Placebo FP-Form A-NS Eyelid Margin Redness Baseline(SD) 1.6 (0.89) 1.5 (0.53) Day 14 (SD) 1.2 (0.45) 0.9 (0.74) Change fromBaseline (SD) −0.4 (0.55)  −0.6 (0.52)  p values 0.1778 0.0051 FP-FormA-NS vs. Placebo −0.2 (−0.8, 0.4) p = 0.5000 (95% CI) Eyelid DebrisBaseline (SD) 1.8 (0.45) 1.6 (0.70) Day 14 (SD) 1.2 (0.45) 0.7 (0.67)Change from Baseline (SD) −0.6 (0.55)  −0.9 (0.88)  p value 0.07050.0100 FP-Form A-NS vs. Placebo −0.3 (−1.2, −0.3) p = 0.5000  (95% CI)Eyelid Discomfort Baseline (SD) 1.8 (0.45) 1.6 (0.52) Day 14 (SD) 1.4(1.14) 0.9 (0.88) Change from Baseline (SD) −0.4 (0.89)  −0.7 (1.16)  pvalues 0.3739 0.0886 FP-Form A-NS vs. Placebo −0.3 (−1.6, 1.0) p =0.6221 (95% CI)

TABLE 13 Composite score of Eyelid Margin Redness, Eyelid Debris, andEyelid Discomfort at 14 Day of treatment with fluticasone propionateform A nanosuspension of the invention (FP-Form A-NS) versus placeboComposite Eyelid Debris, Redness & Discomfort Placebo FP-Form A-NSBaseline (SD) 5.2 (1.30) 4.7 (0.82) Day 14 (SD) 3.8 (1.48) 2.5 (1.90)Change from Baseline (SD) −1.4 (0.55)  −2.2 (1.62)  p values 0.00460.0020 FP-Form A-NS vs. Placebo −0.8 (−2.4, 0.8) p = 0.3095 (95% CI)

TABLE 14 Composite VAS score of dry eye symptoms: eye dryness,burning-stinging, foreign body sensation, itching, photophobia, pain andblurred vision, at 14 Day of treatment with fluticasone propionate formA nanosuspension of the invention (FP-Form A-NS) versus placeboComposite VAS score Placebo FP-Form A-NS Baseline (SD) 41.8 (29.72) 44.8(17.81) Day 14 (SD) 32.9 (27.17) 26.1 (18.05) Change from Baseline (SD)−8.9 (9.37)  −18.8 (19.73)  p values 0.1005 0.0147 FP-Form A-NS vs.Placebo −9.9 (−30.2, 10.5) p = 0.3142 (95% CI)

Example 9

Evaluation of the Stability of the Nanosuspension of Example 2

The nanosuspension composition prepared in example 2 was subjected tostorage stability testing by storing the nanosuspension at threedifferent temperatures and humidity conditions (5° C., 25° C./40% RH;40° C./25% RH) The resuspendability of the nanosuspension, the contentof fluticasone propionate, the particle size distribution and thecontent of benzalkonium chloride were assessed at 1 month and 3-monthtime-points (see results reported in Example 3 and Tables 2 and 3), at5-month time point at 40° C. (Table 15) up to 12 months at 5° C. and 25°C. (Table 16).

The results reported in tables 15 and 16 show that the nanosuspensionwas physically and chemically stable upon storage. No change in physicalappearance of the nanosuspension upon storage was noticed. Thenanosuspension did not show any sign of chemical degradation as thechemical assay of fluticasone propionate was well within the limit of90%-110% of the label claim upon storage. The related substances andtotal impurities remained within the specified limits of not more than4%, upon storage.

Particle size distribution was analyzed using a Horiba LA-950instrument.

TABLE 15 5-month time-point stability data T0 T = 5-month Parameter n/a40° C. 25% RH Fluticasone propionate 105.6% 104% assay FP Relatedsubstances 0.0% 0.11%  (total) Resuspendability n/a Resuspends BAKcontent 99.1% 103% PSD results (μm) Mean 0.846 0.82 Median 0.425 0.50Mode 0.362 0.42 D₁₀ 0.202 0.23 D₉₀ 2.219 1.84

TABLE 16 12-month time-point stability data T = 12-month T0 25° C.Parameter n/a 5° C. 40% RH Fluticasone 105.6% 105% 107% propionate assayFP Related 0.0% 0.61%  0.48%  substances (total) Resuspendability n/aResuspends Resuspends BAK content 99.1% 101%  96% PSD results (μm) Mean0.846 0.90 0.86 Median 0.425 0.45 0.45 Mode 0.362 0.36 0.36 D₁₀ 0.2020.21 0.21 D₉₀ 2.219 2.16 2.08

1-15. (canceled)
 16. An ophthalmic aqueous nanosuspension administrable topically onto eyelids, eyelashes or eyelid margin consisting of: (a) 0.001% to 1% w/w fluticasone propionate Form A nanocrystals; (b) 0.50% w/w methylcellulose 4000 cP; (c) 0.2% w/w polysorbate 80; (d) 0.10% w/w edetate di sodium dihydrate; (e) 1.0% w/w boric acid; (f) 0.9% w/w glycerin; (g) 0.01% w/w benzalkonium chloride; (h) 0.055% w/w sodium chloride; (i) hydrochloric acid 1N and/or sodium hydroxide 1N as adjusting agents in an amount sufficient to pH 7.3-7.5; and (j) water q.s. to 100% w/w, wherein said nanocrystals of fluticasone propionate Form A have a mean particle size from 100 nm to 1000 nm and a X-ray powder diffraction pattern including peaks at about 7.8, 15.7, 20.8, 23.7, 24.5, and 32.5 degrees 2θ, further including peaks at about 9.9, 13.0, 14.6, 16.0, 16.9, 18.1, and 34.3 degrees 2θ, and wherein the nanocrystals are nanoplates having the [001] crystallographic axis substantially normal to the surfaces that define the thickness of the nanoplates.
 17. The ophthalmic aqueous nanosuspension according to claim 16 wherein the concentration of fluticasone propionate is from 0.001% to 0.5% w/w.
 18. The ophthalmic aqueous nanosuspension according to claim 16 wherein the concentration of fluticasone propionate is 0.5% w/w, 0.25% w/w, 0.2% w/w, 0.1% w/w, 0.05% w/w, 0.03% w/w, 0.01% w/w or 0.005% w/w.
 19. The ophthalmic aqueous nanosuspension according to claim 16 wherein the concentration of fluticasone propionate is 0.2% w/w or 0.1% w/w or 0.05% w/w.
 20. The ophthalmic aqueous nanosuspension according to claim 16 for use in a method of treatment blepharitis, posterior blepharitis, Meibomian gland dysfunction or dry eye disease wherein the method comprises topically applying to eyelids, eyelashes or eyelid margin an effective amount of the ophthalmic aqueous nanosuspension.
 21. The ophthalmic aqueous nanosuspension according to claim 16 for use in a method of reducing the symptoms and/or clinical signs associated with blepharitis, posterior blepharitis, Meibomian gland dysfunction or dry eye disease wherein the method comprises topically applying to eyelids, eyelashes or eyelid margin an effective amount of the ophthalmic aqueous nanosuspension.
 22. The ophthalmic aqueous nanosuspension according to claim 21 wherein the ophthalmic aqueous nanosuspension consists of. (a) 0.1% w/w fluticasone propionate Form A nanocrystals; (b) 0.50% w/w methylcellulose 4000 cP; (c) 0.2% w/w polysorbate 80; (d) 0.10% w/w edetate di sodium dihydrate; (e) 1.0% w/w boric acid; (f) 0.9% w/w glycerin; (g) 0.01% w/w benzalkonium chloride; (h) 0.055% w/w sodium chloride; (i) hydrochloric acid 1N and/or sodium hydroxide 1N as adjusting agents in an amount sufficient to pH 7.3-7.5; and (j) water q.s. to 100% w/w, wherein said nanocrystals of fluticasone propionate Form A have a mean particle size from 100 nm to 1000 nm and a X-ray powder diffraction pattern including peaks at about 7.8, 15.7, 20.8, 23.7, 24.5, and 32.5 degrees 2θ, further including peaks at about 9.9, 13.0, 14.6, 16.0, 16.9, 18.1, and 34.3 degrees 2θ, and wherein the nanocrystals are nanoplates having the [001] crystallographic axis substantially normal to the surfaces that define the thickness of the nanoplates.
 23. The ophthalmic aqueous nanosuspension for use in a method according to claim 20 wherein the method comprises topically applying to eyelids, eyelashes or eyelid margin the ophthalmic aqueous nanosuspension at least once a day for at least two weeks. 